Three Stories in One

I was skimming an old book I have called You Can Write a Mystery by Gillian Roberts. Don't let the title fool you. This little Writer's Digest book is packed with good, concise info.
Been thinking about this, Gillian Roberts touches on it, but I am running a bit more on my own.
Crime novels are actually three stories:
First: what physically happened--- what we as readers see of the crime
Second: The theory of what happened-- what eveyone but the sleuth believes went on
Third: What actually happened and why-- the real facts the sleuth uncovers by the story's end

So-- what actually happened is masked, misleading everyone but your sleuth to a the false theory of what happened. But Things Don't Fit and your sleuth knows it. Clues shine through for her, and with her special skill set she uncovers the real story. And that special skill set is why she is the only one that could do it.

Hmmm.